<template>
<!-- 滑动验证码 -->
  <div ref="dragDiv" class="drag">
    <div class="drag_bg"></div>
    <div class="drag_text">{{ confirmWords }}</div>
    <div ref="moveDiv" :class="{'handler_ok_bg':confirmSuccess}" class="handler handler_bg"
         style="position: absolute;top: 0px;left: 0px;" @mousedown="mousedownFn($event)"></div>
  </div>
</template>

<script>
  export default {
    data () {
      return {
        beginClientX: 0, /* 距离屏幕左端距离 */
        mouseMoveStata: false, /* 触发拖动状态  判断 */
        maxwidth: '', /* 拖动最大宽度，依据滑块宽度算出来的 */
        confirmWords: '拖动滑块验证', /* 滑块文字 */
        confirmSuccess: false /* 验证成功判断 */
      }
    },
    mounted () {
      this.maxwidth = this.$refs.dragDiv.clientWidth - this.$refs.moveDiv.clientWidth;
      document.getElementsByTagName('html')[0].addEventListener('mousemove', this.mouseMoveFn);
      document.getElementsByTagName('html')[0].addEventListener('mouseup', this.moseUpFn)
    },
    methods: {
      mousedownFn: function (e) {
        if (!this.confirmSuccess) {
          e.preventDefault && e.preventDefault(); // 阻止文字选中等 浏览器默认事件
          this.mouseMoveStata = true;
          this.beginClientX = e.clientX;
        }
      },
      // mousedoen 事件
      successFunction () {
        this.confirmSuccess = true
        this.confirmWords = '验证通过';
        if (window.addEventListener) {
          document.getElementsByTagName('html')[0].removeEventListener('mousemove', this.mouseMoveFn);
          document.getElementsByTagName('html')[0].removeEventListener('mouseup', this.moseUpFn);
        } else {
          document.getElementsByTagName('html')[0].removeEventListener('mouseup', () => {});
        }
        document.getElementsByClassName('drag_text')[0].style.color = '#fff'
        document.getElementsByClassName('handler')[0].style.left = this.maxwidth + 'px';
        document.getElementsByClassName('drag_bg')[0].style.width = this.maxwidth + 'px';
      },
      // 验证成功函数
      mouseMoveFn (e) {
        if (this.mouseMoveStata) {
          let width = e.clientX - this.beginClientX;
          if (width > 0 && width <= this.maxwidth) {
            document.getElementsByClassName('handler')[0].style.left = width + 'px';
            document.getElementsByClassName('drag_bg')[0].style.width = width + 'px';
          } else if (width > this.maxwidth) {
            this.successFunction();
            console.log('验证成功');
            this.$emit('mousedownFn',this.confirmSuccess)
          }
        }
      },
      // mousemove事件
      moseUpFn (e) {
        this.mouseMoveStata = false;
        var width = e.clientX - this.beginClientX;
        if (width < this.maxwidth) {
          document.getElementsByClassName('handler')[0].style.left = 0 + 'px';
          document.getElementsByClassName('drag_bg')[0].style.width = 0 + 'px';
        }
      }
    }
  }
</script>

<style scoped>
    .drag{
        position: relative;
        background-color: #e8e8e8;
        width: 100%;
        height: 45px;
        line-height: 45px;
        text-align: center;
        border: 1px solid #e2e2e2;
        border-radius: 5px;
        margin-bottom: 20px;
    }
    .handler{
        width: 40px;
        height: 45px;
        border: 1px solid #e2e2e2;
        cursor: move;
    }
    .handler_bg{
        background: #fff url("") no-repeat center;
    }
    .handler_ok_bg{
        background: #fff url("") no-repeat center;
    }
    .drag_bg{
        background-color: #7ac23c;
        height: 45px;
        width: 0px;
    }
    .drag_text{
        position: absolute;
        top: 0px;
        width: 100%;text-align: center;
        -moz-user-select: none;
        -webkit-user-select: none;
        user-select: none;
        -o-user-select:none;
        -ms-user-select:none;
    }
</style>
